1. Field of the Invention
The present invention relates to rock crushing machines and, more particularly, to a system for monitoring, recording, and evaluating a plurality of conditions on a vertical shaft impact crusher.
2. Description of the Prior Art
Vertical shaft impact (VSI) rock crushers provide the rock crushing industry with an efficient and remarkably effective tool for breaking rocks down to a functional particle size. VSI crushers work on the principle that mineral material fed axially into a spinning rotor is flung outwardly at high speed into a chamber surrounding the rotor. Material first ejected from the rotor is retained in the chamber and acts as a rock lining which protects the walls and other parts of the chamber. Thus the breakdown of the rock is caused in great part by the forces of the rocks subsequently ejected from the rotor impacting the rock lining of the chamber rather than other parts of the machine. VSI crushers are described in U.S. Pat. No. 3,970,257 to MacDonald, et al. and U.S. Pat. No. 4,940,188 to Rodriguez.
While one of the great advantages of VSI crushers is the employment of rock-on-rock impact as the disintegrating force, the forces bearing on these machines remain extreme and highly variable. The rotor is a substantial structure rotating at high speed mounted on a bearing cartridge assembly having top and bottom radial bearings. The top and bottom radial bearings are enclosed in a bearing cartridge assembly which includes the main shaft which rotates with and supports the rotor. Smooth operation of the bearing cartridge assembly and rotor depends on the continued health of each of the radial bearings within the cartridge assembly.
The rotor is impelled by a motor typically having three phases, each of which separately draws current, rotating the motor shaft. The continuous operation of the motor requires that each phase operate under an upper temperature limit, and that each motor bearing continues to function smoothly. If excess load is placed on the motor, the amperage draw of the motor will increase, causing a rise in winding temperatures and undesirable stress on the motor.
The continued smooth rotation of the rotor requires that the machine be constantly lubricated. Many VSI crushers are equipped with automated lubrication mechanisms. However, if the lubrication mechanism should fail, or be otherwise neglected, e.g. by failing to refill the lubricant reservoir, the crusher will not be properly lubricated.
Access to the crusher chamber is generally provided through an opening protected by a lid or closed door. An open crusher lid during operation creates a dangerous condition. Similarly, the typical VSI crusher operates using a plurality of V-belts, access to which is provided through an opening covered by a V-belt guard. If the guard is left open during operation of the crusher, the operator can be exposed to a dangerous condition.
The proper reduction of certain minerals requires that the aggregate be fed into the machine at high temperatures. Operation of the crusher when the rotor and crusher chamber are exposed to high feed temperature may adversely affect the operation of the machine.
Understandably, VSI crushers experience regular breakdowns which are frustrating, expensive and time consuming. Generally, the cause of the breakdown of a crusher is determined by a physical inspection of the problem after the breakdown has occurred. In far too many cases, the crusher is only returned to operation after a part is repaired or replaced resulting in an expensive production loss period of downtime. Heretofore, there has been no effective predictive method to monitor the various conditions of an operating VSI crusher so that preventative action can be taken.